Many Web sites/blog use Adobe Flash to customize and enrich the experience of visitors to the site. In order to interact with the flash elements, you will need to install a Flash player on your computer. Flash is compatible with Firefox and is available to download from Adobe. Flash is also great for playing quick, fun games that don’t have to be installed on your computer.

Install Flash Using the Plugin Finder Service

If you are still not sure whether your Firefox has installed adobe flash or not, check this page using your Firefox browser. ADOBE TEST PAGE

If Flash hasn’t already installed, a yellow notification bar will appear above the webpage. Click “Install Missing Plugins” button. The Plugin Finder Service window will appear.

Select the most recent version of Flash listed, then click “Next” button.

Click the check box next to “I have read and agree to the terms of the license agreement” and then click the Install button that will become activated, to begin installation.

If Windows asks to allow Adobe Flash Player to make changes to your computer, click Yes.

When the installation is done, click Finish. The page will reload and you should have Flash installed.

Installing the Flash plugin manually
Windows:

If the above steps do not work, you can try installing the Flash plugin manually:

1. Go to Flash Player download page and download the Flash installer.
2. From the menu at the top of the Firefox windowbar, select FileFirefox and then select the ExitQuit FirefoxQuit menu item.
3. Open the file you downloaded (i.e. install_flash_player.exe), then follow the installer’s instructions.

Mac OS:

1. Go to Flash Player download page and download the Flash installer.
2. From the menu at the top of the Firefox windowbar, select FileFirefox and then select the ExitQuit FirefoxQuit menu item.
3. Open the file you downloaded (i.e. install_flash_player_osx_ub.dmg).
4. In the Finder, open the Adobe Flash Player.pkg to run the installer, then follow the installer’s instructions.

Linux:

The simplest way to install Flash is to use your distribution’s package manager. To install the latest version manually:

1. Go to Flash Player download page at Adobe.com.
2. When prompted, save the file install_flash_player_10_linux.tar.gz.
3. From the menu at the top of the Firefox windowbar, select FileFirefox and then select the ExitQuit FirefoxQuit menu item.
4. Open a Terminal window (in Gnome, click on the Applications menu, select Accessories, and then select Terminal.)
5. In the Terminal window, change to the directory where you saved the file you downloaded (e.g. cd /home/user/Downloads).
6. Extract libflashplayer.so from file you downloaded with the command tar -zxvf install_flash_player_10_linux.tar.gz.
7. As the super user, copy the extracted file, libflashplayer.so, to your Firefox installation directory’s plugins sub-directory. For example, if Firefox is installed in /usr/lib/mozilla, use the command sudo cp libflashplayer.so /usr/lib/mozilla/plugins and then enter your super user password when prompted.

After you install Flash, start Firefox again. To confirm that Flash installed, open the Tools and then select Add-ons. If the installation was successful, Shockwave Flash will appear as an active item with newest version number.

Source: www.mozilla.com